Hi
Coldfire devices load the initial stack pointer (SP) and program counter (PC) values from addresses 0x00000000 and 0x00000004 respectively, so the first instruction that is executed is at the address stored at location 0x00000004.
The device located at location 0x00000000 at reset is determined by the way the chip select is configured - see section 9.4.3 inthe 5234 user manual.
Paul.